We may not have permissions for this.

Reported-by: Mr Jenkins
Fixes: 7dbd38db ("zdtm: set additional groups along with uids and gids")
Cc: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>